Suggested Experiments

Winogradsky Columns and Content Standards:

Below are examples of how Winogradsky columns could address the 2003 State of Delaware Content Standards (italicized).  These examples can be readily applied to more updated versions of the content standards or to standards in different states.

Flow of Matter and Energy in Ecosystems

The supply of nutrients and the efficiency of solar energy transformations are two major factors which ultimately determine the number of organisms and species in an ecosystem.

-Compare the timing, extent, and patterns of microbial phototroph (microbes that utilize light as an energy source) development in Winogradsky columns that have been constructed with or without nutrient amendment (garden fertilizer).

-Examine how light level and light quality affect development of columns.

Each species in an ecosystem occupies the niche for which it is best suited.

-Microbial phototrophs occupy distinct, macroscopically observable zones predominantly set by tolerances for reduced sulfur compounds, oxygen, and light. These variables can be measured allowing a correlation between chemistry and niche.

Changes in Ecosystems

Ecosystems are reasonably stable over long periods of time and tend to have cyclic fluctuations around a point of equilibrium.

-Simulations of acid rain, light deprivation, temperature and other variables can be achieved within Winogradsky columns and their effects on the development of populations after column construction observed.

Ecosystems have a carrying capacity for each species. Overpopulation can lead to depletion of resources and elimination of species.

-After initial column development, a steady state will begin due to nutrient limitations. Columns can be initiated with varying levels of initial carbon and sulfur substrates and the effects on overall density and distribution of organisms determined.

Interactions of Humans Within Ecosystems

All organisms are dependent upon the Earth’s finite supply of material resources to sustain life. Human decisions concerning the use of resources alter the stability and the biodiversity of ecosystems and adversely affect the natural recycling processes which maintain the quality of air water and land.

-Winogradsky columns are prime examples of anthropogenic effects dominating the final nature of an ecosystem. Comparisons between the populations observed in the columns and the site(s) where column inocula were collected will illustrate the nutrient limited nature of most environments. Duplicate columns from the same site with and without fertilizer amendments can also be used to demonstrate anthropogenic effects.

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